1. Field of the Invention
The present invention relates generally to sign linguistics and, more particularly, to providing a system and method of encoding, storing, and retrieving signs in a given sign language.
2. Related Art
Sign languages are developed naturally around the world wherever communities of deaf people exist. In recent years, more and more hearing people have been learning these sign languages for various reasons. Many individuals must learn sign language as a second language and must confront its intricacies and meaning. One problem in sign language teaching and learning is the lack of a practical system for encoding signs into a useable phonetic form.. As hearing people attempt to learn signed languages, though, they are faced with several difficult challenges.
Prior attempts to encode sign language have met with limited success. One approach is to suggest that signs are composed of a location, hand shape and movement. Unfortunately, additional features of sign language, such as palm orientation and non-manual behavior, are ignored.
The four dimensional nature of signed language makes it difficult to represent phonetically or graphically. The first three dimensions are the common spatial dimensions while the fourth dimension is time or the sequence of movement while signing. Students of signed languages experience this difficulty while trying to take notes in class. Prior efforts to encode or translate have had limited success because they have relied on using only two dimensions.
A written system for American Sign Language (ASL) has been introduced by Baker-Shenk and Cokely, and this system can be used efficiently to indicate syntactic relationships of signed utterances. It must be understood that encoding is different than writing. Transcription, by contrast, is the ability to record what has been signed using phonetic citation. The written system falls short of being a useful transcription system. A separate system for representing signs in isolation that shows a sign's phonetic structure would be useful to learn, teach, and understand signing. Students in many sign language classes are taught something about the parametric structure of the language, but are given no application for this information. A basic taxonomy would help students in note taking and vocabulary study. Further, a transcription system would help students build a model of the language as they try to digest the information that is presented to them in class. In pedagogical application of the transcription system, there are three types of sign language materials. These include printed, video taped and computerized materials.
Books and other printed materials have drawbacks when it comes to conveying understanding of sign language. The pages are flat and their contents are static. They typically use actual photographs of actual signers or simple line drawings.
As the pictures cannot move and since motion is crucial to signing, various techniques have been developed to present four dimensional motion in a two dimensional form. Ribbon arrows, dotted lines, and multiple frames are among the different solutions. While these solutions are helpful, they still only simulate three dimensionality in a two dimensional medium. They commonly describe the sequential movement of the signing movement, or the fourth dimension (time). Some signs cannot be thus displayed with pictorial information because the additional dimensions are missing.
In other words, many dictionaries give a narrative description of each sign. Unfortunately, written descriptions can be and sometimes are as obtuse and confusing as the pictures themselves. An additional problem in dictionaries is that of dominance. When a right-handed person signs, his or her right hand is dominant. This dominant hand takes on the larger part of the signing load, functioning alone in one-handed signs, performing the major action and unbalanced two-handed signs. Likewise, when most left-handed people sign, their left hand performs the dominant functions. In the dictionaries, right dominance is presumed and can cause difficulties for left dominant signers. With pictures, it is simple mentally to flip an image; however, with narrative descriptions, phrases like "move your right hand" or "press your left arm" can cause students difficulty.
Video tape and video recordings have the advantage of being able to represent signs in motion. Unfortunately, videotaped renditions of signed symbols suffer from the ability to provide quick access. A student cannot simply open up a video text and turn to a specific example sign. Fast forwarding, rewinding, and time codes become the only way to find a particular segment. Thus, video tapes become too cumbersome to be of practical value in a real time situation.
Video images can now be transferred to a computerized manipulation with the introduction of such software programs as "QuickTime," developed and produced by Apple Computers, and MPEG Digital Video Technology. Both provide full computerized motion of signs. Computers provide the ability to present multimedia examples of the signs. Computers can present the information as digital video, still pictures, text, and sound. Digital video still has some drawbacks. One drawback is the same as with using video tapes, which is the requirement for special equipment. The most significant problem however is that of storage. The size of a full motion, digitized sign can range from several hundred kilobytes to several megabytes. Furthermore, digital video, once compressed, can sometimes be quite grainy. An example of a sign language dictionary put on CD-ROM did include over 2,000 signs on one disc, but the visual clips were so unclear or grainy so they were not very useful. Yet the computerization of the signing language with the power of locating a particular sign, once properly defined, is highly desirable.
Encoding the acoustic signs of a spoken language requires specific knowledge of the vocal gestures of which the words are composed. An accurate written version of an English utterance is distinctly different from an phonetic or phonological transcription. Both represent something a person actually said, but they represent different kinds elements.
Accordingly, what is needed is a method and system for encoding individual signs in a manner that allows a user to readily identify the sign upon review or locate the sign in a searchable data base that uses a search engine based on the transcription method.